We studied the phylogeography of the Sahara frog in North Africa. We widely sampled frogs from Morocco to Tunisia (195 individuals) and sequenced two mitochondrial (16S and CO1) and one nuclear (Rag1) genes. Our results confirm that Moroccan populations of Pelophylax saharicus are genetically distinct from Algerian ones. Specimens from Alger and Djelfa (central Algeria) are genetically closer to Moroccan specimens than to east Algerian ones, and the split between these two lineages may have occurred approximately 2.6 Mya. A similar pattern of differentiation was observed in several other species and was hypothesized to be linked to the formation of the fossil island called the 'Edough Peninsula' in eastern Algeria around 4.2 Ma and then to have been reinforced by Pleistocene climatic changes. At the Moroccan scale, we found a low level of genetic diversity and no clear phylogeographic pattern within P. saharicus. However, our SAShA analyses revealed a mixture of random and underdistributed haplotypes, which may indicate a complex population genetic or biogeographic history.

Recent integration of ecological niche models in phylogeographic studies is improving our understanding of the processes structuring genetic variation across landscapes. Previous studies on the amphibian Bufotes boulengeri boulengeri uncovered a surprisingly weak intraspecific differentiation across the Maghreb region. We widely sampled this species from Morocco to Egypt and sequenced one nuclear and three mitochondrial (mtDNA) genes to determine the level of genetic variability across its geographic range. We evaluated these data with ecological niche modeling to reveal its evolutionary history in response to climate change during the Quaternary. Our results highlight some mtDNA phylogeographic structure within this species, with one haplogroup endemic to coastal Morocco, and one haplogroup widely distributed throughout North Africa. No or little genetic differentiation is observed between isolated populations from the Hoggar Mountains, the Sabha district and the islands of Kerkennah and Lampedusa, compared to others populations. This can be explained by the expansion of the distribution range of B. b. boulengeri during glacial periods. This might have facilitated the species’ dispersal and subsequent gene flow between most North African localities.

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